1. Field of the Invention
The present invention relates to a communication method which is preferably applied to a case in which a video game is executed among a plurality of persons being at separated positions in one house, and a communication apparatus to which this communication method is applied.
2. Description of the Related Art
A video game machine in which a storage medium which stores (records) a game program therein is loaded is connected to a display device such as a television receiver, and an operation unit such as a joystick connected to a game machine is operated to execute a game. In this case, a plurality of operation units are prepared, and various interplay games each of which is executed among many persons such as two, three, or more persons also exist.
Conventionally, when an interplay game is executed among many persons, the operation states of the operators are generally displayed on one display device at once, and all the operators generally see the display of the display device at once. For example, in case of an interplay game such as a car race game, the positions of cars operated by operators are displayed on one screen, and the race is executed on the screen displayed on the display device.
In contrast to this, a game having such hiddenness that operation states of operators cannot be known by other operators depending on the contents of the game also exists. For example, such a game corresponds to a trump game such as a poker game or a mah-jongg game. In such a case, display devices are prepared for the respective operators, the displays of the display devices cannot be seen from other operators (or they may be able to be seen from the other operators depending on the contents of the game) to execute the game.
When a plurality of display devices are prepared to execute an interplay video game, the display devices must be respectively connected to a game machine body, the configuration is complex disadvantageously. Conventionally, an apparatus for executing an interplay game by using the plurality of display devices is designed to be applied to a commercial large-scale apparatus which is mainly installed in a game arcade, and cannot be easily installed in a general house or the like.
More specifically, for example, a plurality of television receivers are frequently held in a general house, and the television receivers are ordinarily installed in different rooms, respectively. In order to execute an interplay video game, the receivers in the rooms are connected to the game machine body through different dedicated signal lines. The game operation units installed in the rooms must be also connected to the game machine body through different dedicated signal lines, and the connection configuration is very complex disadvantageously.
FIG. 11 is a diagram showing a conventional installation state. In a house 100, first, second, third, and fourth rooms 101, 102, 103, and 104 are prepared, receivers 2A, 3A, 4A, and 5A for displaying a video game image and game operation devices 2B, 3B, 4B, and 5B are arranged in the rooms 101 to 104, respectively. As the receivers, image display devices each constituted by, e.g., cathode ray tubes, image display devices each constituted by a liquid crystal display panel, or the like are used. As the game operation devices, for example, input devices or the like on which joysticks or a plurality of keys are arranged and which are prepared for various game operations are used. In the first room 101, a game machine body 1 is arranged. In the game machine body 1, a storage medium which stores an arbitrary game program (the program of a game executed among four persons) therein is loaded.
As connection between the game machine body 1 and the receivers and the game operation devices in the rooms, for example, as shown in FIG. 12, the other ends of the signal lines having one ends connected to the game machine body 1 are connected to the different receivers and the different game operation devices. In the example shown in FIG. 12, an output switching device 1C is connected between the game machine body 1 and the receivers 2A, 3A, 4A, and 5A, and an input processing device ID is connected between the game machine body 1 and the game operation devices 2B, 3B, 4B, and 5B.
When all the receivers and operation devices prepared as described above are independently connected to the game machine body, and the respective receivers are arranged in different rooms, a large number of very long signal lines are required. In addition, the large number of signal lines must be arranged in the house, and the connection configuration is very complex disadvantageously.
It is an object of the present invention to simplify a connection formed when a video game is executed by a large number of persons.
According to the first aspect of the present invention, there is provided a communication method including the steps of:
making it possible to communicate game program execution means for executing a game program having at least a video image with a plurality of display means and a plurality of operation means through a predetermined interface;
defining a predetermined cycle as communication between the interface and the respective display means and the respective operation means and setting a period in which isochronous transfer is performed in the cycle and a period in which asynchronous transfer is performed in the cycle;
dividing the period in which isochronous transfer is performed into regions for transmitting video data to the respective display means to independently execute transmitting operations;
independently transmitting operation data from the respective operation means in the period in which asynchronous transfer is performed; and
causing the display means and the operation means to independently communicate with the game program execution means by using the same communication path and performing independent operations in the respective operation means and independent display operations in the respective display means for a common game program executed by the game program execution means.
According to this communication method, the interface and the respective display means and the respective operation means are connected with a common bus line on which isochronous transfer and asynchronous transfer can be performed in a time division manner, so that respective data communication operations can be performed between one game program execution means, the respective display means, and the respective operation means.
According to the second aspect of the present invention, there is provided a communication apparatus including:
game program execution means for executing a game program having at least a video image;
a plurality of display means for displaying a video image based on the game program executed by the game program execution means;
a plurality of operation means for instructing execution of the game program in the game program execution means; and
communication control means for performing data communication between the program execution means, the plurality of display means, and the plurality of operation means, defining predetermined cycles as data communication states to perform communication, setting a period in which isochronous transfer is performed in each cycle and a period in which asynchronous transfer is performed in each cycle, performing communication in divided regions for transmitting video data to the respective display means in the period in which isochronous transfer is performed, and independently communicating operation data from the respective operation means in the period in which asynchronous transfer is performed.
According to the communication apparatus, the game program execution means and the respective display means and the respective operation means are connected with a common bus line on which isochronous transfer and asynchronous transfer can be performed in a time division manner, and a communication state on the bus line is controlled by the communication control means, so that a system which can perform communication of respective data between one game program execution means, the respective display means, and the respective operation means.